I feel like it's the whole series, really. But this one in particular.
Every series finale. Every blooming series finale. The World/Universe/Gallifrey once again comes to an end. And once again the Doctor fumbles his way to a solution.
The trouble is, after The Parting of the Ways, there was nowhere more to go for end-of-series finales. An end-of-the-Universe battle between Daleks and a godlike Rose Tyler, involving a man brought back from the dead and battalions of Dalek space ships being vaporised - after that, merely turning up to 11 was never going to help. How can you, when the dial's already switched up to 12, and then somebody's smashed the amp up with the power of the Vortex at the heart of a Tardis? And how can you compete with a fully-formed companion with a believable back-story, like Rose, when you're a cardboard cut out "Impossible Girl" of a companion?
And so every series finale becomes an exercise in pro-celebrity shark jumping. Well, the shark has been well and truly jumped. It's time to kill the shark. Or, at least, cut the water-skis up. Or close the water-sports company.
I tell you, If I see the clouds roll away from the Earth, leaving it safe and pristine once more, I'll scream. Yesterday the assembled consciences of everybody who had ever lived on the planet, embedded into a bunch of revamped Cybermen, collectively ascended into the heavens and sacrificed themselves to save the world. And, apart from a fleeting moment of recognition of the Brigadier, I didn't care. I couldn't work out whether this was because the relationship between Clara and Danny was so poorly drawn, or whether it was the ludicrous device of Cybermen ascending into the heavens with jet-powered heels. Honestly, it was bad enough with levitating Daleks. But those Cybermen - how were they going to maintain aerodynamic stability?
And then the idea that every fragment of a Cyberman contains the instructions to build a Cyberman from scratch - sure that was clever, a reference to the DNA in every human cell. But how did these shiny-headed Von Neumann machines manage it? OK, the Cyberman pollen, falling into a graveyard in the ironstone fields of Northamptonshire - no problem. Raw materials for steel and glass aplenty. But in London? Seriously? The pollen, grabbing the available materials, would have been turning out china dolls. This is meant to be Science Fiction, not fantasy. There's a difference.
But there's something more deeply wrong about the Cybermen since the series returned - even in Rise of the Cybermen / The Age of Steel, when Roger Lloyd Pack played a brilliant creator who ended up as part of his own engineering. And it's this. The original Cybermen were the masters of their own destiny (I use the masculine throughout, in line with their naming convention). They chose to become androids, as a way of ensuring their own immortality. It was a Faustian contract with technology. But Lumic's creations, and Missy's children - they've no choice. They're not evil creatures - they're as much victims as the people they're deleting. Something is lost there.
Quite liked Missy, though. Maybe there's something about evil, manipulative, power-crazed women I like. Can't imagine why. Michelle Gomez is superb, dancing as the world sees an alien resurrection. But the insanity, the use of the word "bananas". Left a nasty taste. You can do bad things without being insane. In fact, most bad things are done by sane people in the real world.
And I love Peter Capaldi as the Doctor. He's a brilliant Doctor - sharp, funny, ambivalent, with those lovely dark shades. But he's let down by the writing, the concept, the not-quite-right special effects. The Cybermen lifting off into space weren't awesome, they were laughable. They might as well have saved a few quid and just pulled a load of Cyberman models up into the air on strings.
Far as I'm concerned, the whole series has died on its feet. We need fewer strained relationship issues, fewer instances of the whole Universe being at risk, and more running down tunnels and climbing up ventilation shafts. Or we just accept it's never gonna regenerate.